Apparatus for producing highly stretchable twist cotton yarn

ABSTRACT

A method to produce highly stretchable twisted cotton yarn, wherein a single yarn is plied in two or more folds, and twisted in the direction of the single yarn twist, then the resulting plied yarn is treated in a bath with an alkaline solution, neutralized by acid, and water-washed, whereupon the yarn is impregnated with thermosetting resins, squeezed, dried, heat cured, and then straightened out and untwisted, thereby giving it a twist in the direction opposite to that of the plied yarn, thereby to produce a highly stretchable twisted cotton yarn.

United States Patent [191 Isirkel et al.

[111 3,722,204 [451 Mar. 27, 1973 APPARATUS FOR PRODUCING HIGHLYSTRETCHABLE TWIST CO'ITON YARN [76] lnventors: Elena Ernestovna Tsirkel,ulitsa Bela Kuna, l9; Ljudmila Nikolaevna Stepanova, ulitsa Schevchenko,l7; Antonina Vasilievna Schiptsova, ulitsa Bestuszhevskaya ll; NinaAlexandrovna Tsareva, ulitsa Basseinaya, 63; Andrei MaximilianovichNessler, ulitsa Bela Kuna, 19, all of Leningrad; Idal AizikovichVishnyak, ulitsa Universitetskaya, 371, kv. 39, Tashkent, all ofU.S.S.R.

[22] Filed: Nov. 9, 1970 [21] Appl. No.: 87,944

[52] U.S. Cl. ..57/164 [51] Int. Cl. ..D02g 3/40, DOlh 13/30 [58] Fieldof Search ....57/34 R, 34 HS, 35, 156, 162,

[56] References Cited UNITED STATES PATENTS 2,254,741 9/1941 7 Hansen etal .L ..57/164 X 2,449,215 9/1948 Goldthwait et a1. ..57/164 3,127,7324/1964 Brown et al. ..57/164 3,285,690 11/1966 Cooper et a] ..57/164 X3,299,486 l/l967 Meyers et a]. ..57/164 X 3,381,465 5/l968 Kingsbery etal ..57/164 3,403,504 10/1968 Himalainen et al. ..57/164 3,508,4214/1970 Dimond et a] ..57/35 X Primary ExaminerDonald E. WatkinsAttorney-Holman & Stern ABSTRACT A method to produce highly stretchabletwisted cotton yarn, wherein a single yarn is plied in two or morefolds, and twisted in the direction of the single yarn twist, then theresulting plied yarn is treated in a bath with an alkaline solution,neutralized by acid, and water-washed, whereupon the yarn is impregnatedwith thermosetting resins, squeezed, dried, heat cured, and thenstraightened out and untwisted, thereby giving it a twist in thedirection opposite 'to that of the plied yam, thereby to produce ahighly stretchable twisted cotton yarn.

1 Claim, 1 Drawing Fi gure APPARATUS FOR PRODUCING HIGHLY STRETCHABLETWIST COTTON YARN BACKGROUND OF THE INVENTION The present inventionrelates to processes for producing cotton yarn, and more specifically toa method of manufacturing highly stretchable twisted cotton yarn.

The present invention is most successfully used to make yarns employedin the production of woven or knitted stretch wear, gloves, and hosiery.

I DESCRIPTION OF PRIOR ART Known at present is a method of manufacturinghighly elastic twisted cotton yarn, including the following operations:plying a single yarn in two or more plies, twisting the plied yarn intwister frames, making the plied twisted yarn into skeins or bobbins,impregnating the yarn with crosslinking therrnosetting resins, furtherheat curing of these resins, and finally, untwisting of the yarn intwister frames in the direction opposite to the twist of the plied yarn,with simultaneous winding of the highly stretchable yarn onto twisttubes or spools (see, for example, US. Pat. No. 3,127,732, Cl.57-l64) Inthis method each operation of yarn processing is done separately,passing from one type of equipment to another.

Since in this conventional method the plied and twisted yarn isimpregnated without any previous preparation prior to impregnation, manyshort inter- 7 molecular links are formed therein, resulting inexcessive stiffness of the yarn and a significant drop in its strength.Besides, owing to some nonumifonnity in the yarn diameter and twistunevenness inherent in it, the yarn obtained by the conventional methodhas sections with helical coils, i.e., twist-retaining sections, andthis drawback substantially worsens the yarn quality. Also, the priorart multistage process of making the yarn reduces labor efficiency, anddoes not allow organizing a continuous process. i Y

The basic object of the invention is to develop a method of producinghighly stretchable twisted cotton yarn and a device to realize it, withthe introduction of such preparatory operations of yarn treatment priorto its impregnation, that would permit obtaining a soft and strongeryarn in a continuous process, at the same time using equipment of asimple design and ofiering high productivity.

With this object in view, in the present method of producing highlystretchable twisted cotton yarn, con sisting in plying a single yarn intwo or more plies, and twisting it in the direction of twist of thesingle yarn, whereupon the thus obtained plied yarn is pretreatedaccording to the invention and subsequently impregnated withthermosetting resins, squeezed, dried, heat cured, and finally untwistedwith simultaneous spooling of the finished highly stretchable yarn. Ac-

cording to the invention, prior to impregnation the plied yarn istreated in an alkaline solution bath; the plied yarn is passed atconstant rates of its entry into,

' and exit from, the bath, and then neutralized, acidated,

and water-washed, and the yarn is heat curedand is straightened out;subsequently after its untwisting it is given a-twist opposite to thatof the plied yam. Alkaline pretreatment prior to impregnation, accordingto the invention is realized with a sodium bicarbonate solution. Suchpreparatory yarn treatment prior to its impregnation provides fordecreasing its undesirable stiffness and obviates strength loss owing toformation of longer intermolecular links.

The amount of back twist is expediently made to be in the range from 5to percent of that of the plied yarn.

This obviates the formation of helical coils (twistretaining sections)in the finished yarn.

The device employed to realize the proposed method comprises immovablerods located at the bottom of the baths for treating the yarn with analkaline solution, its neutralization by acidation, washing,impregnation, and squeezing, these rods being passed about by the yarn,and providing for intensification of the process. An arrangement forheat curing the yarn includes a heat-crimping tube, at whose exit thereis installed an attachment for straightening the thread before itsuntwisting.

The immovable rods substantially promote intensification of the yarntreatment processes, as the solution captured by the yarn and gettingbetween it and the rod is pressed into the yarn, which would not takeplace in case of prior art apparatus having yarn passage about revolvingrollers. The heat-crimping tube ensures a long time of curing (up to 45minutes) within a continuous process. The attachment to straighten outthe yarn is vital, because the crirnped yarn emerging from the tube doesnot lend itself to direct untwisting (because of possible snarls, knots,etc.).

DESCRIPTION OF PREFERRED EMBODIMENTS For a betterunderstanding of theinvention, considered below is a particular exemplary embodiment thereofwith references to the appended drawing, which shows a schematic diagramof the device for realizing the method according to the invention.

The sequence of a proposed method is as follows: ply yarn unwound from apackage is subjected to twisting. Then this plied yarn is in a sequencetreated in baths with an alkaline solution such as of sodium bicar- 1bonate, a dilute solution of acid, and water, whereupon the yarn isimpregnated with a thermosettingresin, squeezed, dried, and heat cured.After its heat curing the yarn is straightened, untwisted, and givensome twist in the direction oppositeto that of the plied yarn twist,with simultaneous winding of the finished highly stretchable yarn.

The highly stretchable twist yarn is produced in the following way. Yam4 made in two ormore-plies is unwound by a pair of rollers 3 from abobbin 2 placed on a delivery spindle 1 which twists the yarn. The twistyarn 5 is drawn by a pair of rollers 6 through a bath 7 with an alkalinesolution of NaOH grams/liter), whereupon the yarn passes about a fixedrod 8. The rates of rotation of rollers 3 and 6 are equal, and the timeof yarn passage through the bath depends on-the yarn thickness. Then apair of rollers 9 pulls the yarn througha bath 10 filled with a sodiumbicarbonate solution, the :yarn againpassing about a fixed rod 8. Next,a pair of rollers 11 pulls the yarn through a bath 12 with a dilute acidsolution, and a pair of rollers 13 pulls it through a water bath 14 towash the yarn in water. A pair of rollers 15 takes the yarn through abath heater plates 19, where it is dried, and after passing through afunnel 20 disks 21 stuff the yarn into an arrangement 22 for its heatcuring. The arrangement includes a tapered heat-crimping tube 23 whosevolume ensures a heat curing time of up to 45 minutes, while its taperprovides for free movement of the crimped yarn along the tube. i I

' From tube 23 yarn is pulled by a pair of delivery rollers 24, prior towhich it passes through an attachment 25 for its straightening. Thisattachment consists of a felt layer 26 having a slit 27 through whichthe yarn is pulled.

Other designs of the straightening attachment are also possible, as forexample, systems of rollers or combs.

The straightened yarn with long intermolecular links formed therein,which issues from rollers 24, is subject to untwisting and backtwistingby spindle 28 with simultaneous winding of the finished highlystretchable yarn 29 to a tube 30 placed on this spindle. As the yarn isuntwisted, it is at the same time given a twist in the directionopposite to that of the plied yarn, the amount of the back twist beingfrom to percent of that of the plied yarn twist. If the yarn is givenless than said 5 percent of back twist, said helical coils which areundesirable may remain in the finished yarn, and in case it is givenmore than 10 percent, the yarn. acquires a greater stiffness and asmaller bulk.

Thus, the yarn produced by the above-described method features softness,high elasticity and stretchability which is stable against multiplewashings, high water and moisture absorption which is near to that inordinary cotton yarn, and high resistance to microorganisms and rotting.

" Being close'in its elasticity to stretchable yarns made of syntheticfibers, the finished yarn of the present invention has an undoubtedadvantage over them from certain hygienic and other considerations.

What we claim is:

,1..An' apparatus for producing highly stretchable twisted cotton yarncomprising: means to ply single cotton yarn in a plurality of folds andtwist the yarn so plied in a direction of the single yarn twist; meansto pass plied yarn in a series of successive liquid baths, each bathbeing provided in a container having a fixed rod about which the pliedyarn is arranged to pass, a first of said liquid baths containing analkaline solution, a second of said baths containing an acidic solutionfor neutralization, a third of said baths containing water for washingand cleansing the neutralized plied yarn, a fourth of said bathscontaining an impregnating compound to impregnate the plied neutralizedand washed yarn; a means to dry the impregnated yarn and further meansto heat-cure the impregnating compound, said further means being in theform of a heat-crimping tube through which the yarn is threaded, and anattachment for straightening the yarn and means to untwist the yarn inthe direction opposite to said direction of the single yarn twist by apredetermined degree-so as to produce a highly stretchable twistedcotton yarn.

